There is a problem with the eigsolve function. I am on the latest cvs and a 64 bit Linux. Th code A = I(2) B = I(2) C = {} eigsolve(A, B, &C) eigsolve(A, B, C) print C shows the problem and I think it can be solve if geneval.c line 6181 is substituted by something like } else if (r->t != EMPTY && r->t != U_ADDR) { /* optional matrix-pointer */ node_type_error(f, 3, U_ADDR, r, p); } else { const char *rname; rname = (r->t == U_ADDR)? r->v.b1.b->v.str : "null"; A = user_gensymm_eigenvals(l->v.m, m->v.m, rname, &p->err); } inspired by the normal eigenvalue function. I don't know if it is the right fix but at least it runs. Best Andreas -- Andreas Noack Jensen Ph.d.-stipendiat Økonomisk Institut andreas.noack.jensen(a)econ.ku.dk Københavns Universitet http://www.econ.ku.dk/phdstudent/noack/ Øster Farimagsgade 5, bygning 26 Tlf.: 353 23094 1353 København K